A wheelchair is a chair with wheels, designed to be a replacement for walking. The device comes in variations where it's propelled by motors or by the seated occupant turning the rear wheels by hand. Often there are handles behind the seat for someone else to do the pushing. Wheelchairs are used by people for whom walking is difficult or impossible due to illness (physiological or physical), injury, or disability. The earliest record of wheelchairs dates back to the 6th century, as an inscription found on a stone slate in China. Later dates relate to Europeans using this technology during the German Renaissance. Harry Jennings and his disabled friend Herbert Everest, both mechanical engineers, invented the first lightweight, steel, collapsible wheelchair in 1933. Mr Everest had broken his back in a mining accident. The two saw the business potential of the invention and went on to become the first mass-manufacturers of wheelchairs: Everest and Jennings. Their “x-brace” design is still in common use, albeit with updated materials and other improvements.
A basic manual wheelchair incorporates a seat, foot rests, handles at the back and four wheels: two castor wheels at the front and two large wheels at the back. Although the use of a wheelchair greatly increases the mobility and independence of a person with limited physical abilities, the current design of wheelchairs, described above, still leaves a user with many limitations.
One of the major limitations for a person confined to a wheelchair involves access to facilities and areas designed for use by persons of normal physical abilities. The size and maneuvering capabilities of a wheelchair often do not conform to the physical constraints of such facilities. The wheelchair may be too wide to fit in many passages, the turning radius of the wheelchair may be too large for some of the turns, the wheelchair may be unable to traverse certain obstacles (particularly standing obstacles), and so on. As a result, many modern facilities are designed to allow access to wheelchairs, i.e. are designed with wheelchair limitations in mind, and there are even laws requiring many facilities intended for public use to provide for wheelchair access. Nevertheless, a person confined to a wheelchair often encounters situations where the physical limitations of the wheelchair inhibit or even prevent his/her access to facilities or areas he/she wishes to enter, use or traverse. This is often true of private residences or older facilities. Moreover, even in those locations that provide for wheelchair access, the use of these provisions may be cumbersome or unpleasant.
Of particular concern is access to toilet facilities, which is often especially difficult and unpleasant for persons confined to a wheelchair. Not only are most toilets inaccessible for a standard wheelchair, even those that are require the person to transfer himself from the wheelchair to the toilet seat and/or require the intimate assistance of a third party.
It would therefore be desirable to provide a wheelchair adapted to conform to the physical constraints of facilities and areas designed for use by normal persons (especially toilet facilities), while still allowing independent use by a person confined to a wheelchair. Such a wheelchair would be especially useful if it is further adapted to be easy to store, transport and use by a person with limited physical abilities and would be yet more useful if it allowed a person seated on it to use a toilet facility without transferring himself/herself onto the toilet seat.